16x2 LCD shows only black boxes in the bottom line

I realize this is an old topic, but I found it because I was having a similar issue. In my case, it turns out that the eBook example had a pair of switched connections to the LCD. Knowing how the LiquidCrystal() command is configured allowed me to troubleshoot the problem.

For beginners, be sure to use Include Library in Arduino app for LiquidCrystal.

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